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TAChart: Let user add points to ListSource without keeping X-order

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git-svn-id: trunk@23240 -
This commit is contained in:
ask 2009-12-23 14:28:23 +00:00
parent fd45608001
commit 4f2de1c04c
1 changed files with 14 additions and 9 deletions
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23
components/tachart/tasources.pas
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@ -98,7 +98,9 @@ type
constructor Create(AOwner: TComponent); override; constructor Create(AOwner: TComponent); override;
destructor Destroy; override; destructor Destroy; override;
public public
function Add(AX, AY: Double; const ALabel: String; AColor: TColor): Integer; function Add(
AX, AY: Double; const ALabel: String; AColor: TColor;
AInOrder: Boolean = true): Integer;
procedure Clear; procedure Clear;
procedure CopyForm(ASource: TCustomChartSource); procedure CopyForm(ASource: TCustomChartSource);
procedure Delete(AIndex: Integer); inline; procedure Delete(AIndex: Integer); inline;
@ -427,7 +429,8 @@ end;
{ TListChartSource } { TListChartSource }
function TListChartSource.Add( function TListChartSource.Add(
AX, AY: Double; const ALabel: String; AColor: TColor): Integer; AX, AY: Double; const ALabel: String;
AColor: TColor; AInOrder: Boolean): Integer;
var var
pcc: PChartDataItem; pcc: PChartDataItem;
begin begin
@ -438,14 +441,16 @@ begin
pcc^.Text := ALabel; pcc^.Text := ALabel;
UpdateCachesAfterAdd(AX, AY); UpdateCachesAfterAdd(AX, AY);
// We keep data points ordered by X coordinate.
// Note that this leads to O(N^2) time except
// for the case of adding already ordered points.
// So, is the user wants to add many (>10000) points to a graph,
// he should pre-sort them to avoid performance penalty.
Result := FData.Count; Result := FData.Count;
while (Result > 0) and (Item[Result - 1]^.X > AX) do if AInOrder then begin
Dec(Result); // Keep data points ordered by X coordinate.
// Note that this leads to O(N^2) time except
// for the case of adding already ordered points.
// So, is the user wants to add many (>10000) points to a graph,
// he should pre-sort them to avoid performance penalty.
while (Result > 0) and (Item[Result - 1]^.X > AX) do
Dec(Result);
end;
FData.Insert(Result, pcc); FData.Insert(Result, pcc);
Notify; Notify;
end; end;